The ever-growing traffic load in communication networks has been realized for quite some time as a problem that requires a solution. To date, some solutions were suggested to the problem. One such solution was suggested in IESS-501 (Rev. 3) entitled “Digital Circuit Multiplication Equipment Specification 32 kbit/s ADPCM with DSI and Facsimile Demodulation/Remodulation”, 1992. The solution suggested in pp. 27-29 was to decrease the number of bits in the voice channels under overload conditions of the network. When the demand cannot be met by the network, the algorithms will first lose one bit, and then if the demand is still not met, the algorithms may lose a further bit.
Another solution known in the art is a method described in standard G.763 which defines the management of a communication network under varying traffic loads. Essentially, according to this solution a bit is dropped from every algorithm applied in the bearer, and all these dropped bits are collected to a “bank” of bits. When the system load increases, the bits available in the bank can be used. However, if the requirement for bits is further increased and exceeds the number of bits available, each algorithm must “contribute” a further bit to the “bank”. The process continues as described above, until the network requirements are met.
As may be appreciated, these solutions are directed to provide a solution to the overload problems and are not particularly concerned with the provision of neither equalized nor maximized signal quality. In other words, the prior art solutions are directed towards ensuring that traffic will be transmitted through the network, even if the transmission is not carried out in the best possible mode.
U.S. Pat. No. 6,549,515 discloses a method for managing varying traffic load in a telecommunication network, by establishing an instantaneous demand for bandwidth, calculating a total number of bits required for conveying transmissions by all active channels, and comparing them with total number of bits required. Thereafter, and applying a bit rate adjusting mechanism for each one of the active channels according to the algorithm used in that channel.
US 20030012137 describes a packet network congestion control system using a biased packet discard policy. Once a connection and session are established, compressed voice and data packets start flowing between the two end points of the path. A control entity supplies congestion control packets periodically. The control packets provide a heartbeat signal to the codec at the other end of the session. Each codec receiver uses the heartbeat signal as an indication of network congestion. As network congestion increases, routers within the network discard excess packets to prevent network failure. The network discards all packets classified as congestion control packets whenever a flow control mechanism detects congestion or a trend toward congestion. As packets are discarded, the end points renegotiate codec type and/or parameters to realize lower bit rates.
WO 0057606 describes a method for discarding data within an IP-network communications link. Initially, the IP-network communications link is monitored to determine the occurrence of an overload condition. At least some of the data packets transmitted along the IP-network communications link are selected in response to detection of the overload condition, and the selected data packets are discarded from the link, while the remainder of the packets are transmitted. According to the method described in that publication, the packet payloads of data packets are separated into important parameters and less important parameters, and the less important parameters are selected and discarded. When packets of real-time flow sessions are concerned, the selected data packets are those having the same source and destination IP addresses and source and destination ports, and consisting of encapsulated video, audio, etc. signals. Discarding these packets from that link allows that only a single or a few real-time flow sessions are eliminated from the link, while the remaining links' sessions are unaffected.
The disclosures of all references mentioned above and throughout the present specification are hereby incorporated herein by reference.